There is no way to know without knowing the respective team needs, but a likely top 3 RB (Charles) figures to have more value alone than a low end WR1 and a rookie RB on a team that demonstrated little ability to run block last season. Effectively, Maclin gives you a WR4 for free.
I was thinking along the same lines. This is a trade that was proposed to me. I have Charles and Maclin. I also have Alfred Morris (every week starter) and Chris Ivory (will have to wait and see how much he'll be utilized) Maclin will most likely be on my bench all season as my WR corps is pretty strong. thanks for your reply.